1. Field of the Invention
The invention relates to a combined offshore system for generating electricity from wave motion, primarily ocean or sea waves as well as from wind, the extracted energy being converted into useful energy. Existing devices will be used to convert the wave energy into useful energy.
2. Description of the Related Art
Reference is made to the following publications: U.S. Pat. No. 6,476,511 describes an apparatus for extracting power from ocean waves that comprises a number of buoyant cylindrical body members connected together at their ends to form an articulated chain-like structure. Each pair of cylindrical members is connected to an adjacent pair by a coupling member, which permits relative rotational movement of the cylindrical members about at least one transverse axis.
U.S. Pat. No. 2003145587 describes a wind and wave energy plant, comprising a windmill with a rotor and a wave-actuated water pump that can drive a turbine. In this patent it is disclosed how by means a firmly anchored mill tower, it is possible to achieve a combination of a better utilization of the wind energy, as the mill rotor is raised to a height with strong winds, and at the same time a better utilization of the wave energy, as by pumping seawater into the mill tower and by storing the water there it is possible to achieve a large pressure drop across the turbine wheel.
WO2006010783 describes wind, wave and current power stations with different foundation solutions and methods for manufacture, transport, installation and operation of these power stations.
In plants for extraction of energy from wind and waves, the final price of the energy produced depends partly on the construction costs and partly on the overall efficiency. The known plants are generally rather complex and therefore expensive to construct, and moreover the efficiencies achieved are not optimum.